Dim green light on magsafe charger with new battery + DC-in board

The laptop works fine when it has battery (only problem being that the battery takes a really long time to charge back up even a few %, and the magsafe has the dim light). If the battery is left to completely empty the laptop won't turn back on, even after being left for days to charge...However, once a new battery is put in which has charge in it, it works again (with the same problem with the slow charging and dim green light)

3 Answers

By chance did something spill onto the system or did you sit the system down on a wet surface?

I would start off by downloading this little gem of a tool to see more clearly what is going on coconutBattery. Tell us what it tell you.

I suspect you likely have some corrosion on the main logic board around the FET's or one of the FETs is failing. Look between the fans the five pin'ed devices are the FET's (4). Here's a good image for reference Logic Board

Update

Well some good news here SMC services area working and the Battery is in good shape.

The bad news is it looks like the charging logic has a problem on the main logic board. As you suspect liquid damage I think you need to do a teardown of the system to repair or replace the keyboard and clean up any spillage on the logic board (both sides). You'll need distilled water (not tap) and high grade of Isopropyl alcohol (85% or better). Some cotton swabs (Q-Tips) & a soft toothbrush to scrub some areas. First remove the battery and then use the distilled water on any stained areas to clean up the corrosion afterwards go over the same areas again with the alcohol to clean any oil or grease and to act as a drier to help in removing the last traces of water. Make sure to let the system dry out a good day before powering up again

For now lets pop off the bottom cover and inspect the FET's and the charging circuit which is located between the fans. Do you see any corrosion or damage using the picture I gave you as reference?

Hi Dan, thanks for the reply. Well...here's the thing....I bought it off ebay so I can't be sure, but after doing some reading I'm guessing that it has had water damage because the keyboard lights are only working in the middle (if i would have known this was a sign of water damage I never would have bought it!!)

I'm not sure which ones are the FET's? I can't see any with five pins?

If it is corrosion where do I go from here? Would cleaning the logic board be a good idea?

With battery the macbook (A1342) didn't boot and magsafe connector showed a very faint green led.

After disconnecting the battery, I could get the Macbook to boot. No magsafe led visible.

I guessed the battery (status: service required) had finally shorted internally causing the dim led. I ordered a new battery: Nope. Same problem.

The issue finally proved to be the Magsafe port within the Macbook. It had shifted a tiny bit inwards due the two Torx screws holding it not being very tight. The magsafe connector seems to connect (magnetic), but the full electric connection actually got obstructed by the outside of the lower shell of the Macbook. Due to this the pins didn't all connect correctly. I guess the middle pin of the connector simply didn't link. (I was able to boot without battery remember, so two outer pins must have connected alright)

Shifting the Magsafe port connector further out and retightening the screws (one of them below the lcd data cable connector) solved it for me.

It happened to me like 15mins ago so that brought me here. I was thinking why its in dim light. I was like maybe to supply of power from the house is not enough. But no, so i pressed shift option control and power button at the same time, and a miracle happened. The charger turned to red light and when i opened it its charging properly..